Question

what is difference between saturated and unsaturated solution?

Answer 1

Here is your answer:
An unsaturated solution is one in which additional solute can still be dissolved without heating. As more and more solute dissolves into the solution, a state is eventually reached where it seems that additional solute can no longer be dissolved, creating a saturated solution.

However, this does not mean that no solute continues to dissolve into the solution. Rather, an equilibrium is established where as more solute dissolves into the solution, an equal amount of solute is precipitated out of the solution. Hence no matter how much additional solute is added to the solution and how vigorously one stirs, the concentration of the solution would not increase unless heat is applied.

Answer 2

And in case the solution has less than the maximum amount that can we dissolve the solution is called an unsaturated solution.

A saturated solution is that solution in which the maximum amount of solute has been dissolved at a particular temperature.